people = 30
cars = 30
buses = 15

if cars > people 
  puts "We should take the cars."
elsif cars < people
  puts "We should not take the cars."
else 
  puts "We can't decide."
end

if buses > cars
  puts "That's too many buses."
elsif buses < cars
  puts "Maybe we could take the buses."
else
  puts "We still can't decide."
end

if people > buses
  puts "Alright, let's just take the buses."
else
  puts "Fine, let's stay home then."
end

#主要将的是if,elsif ,else的运用，都是条件语句，首先如果满足if的条件的话就输出if下面的字符，如果不满足if的条件但是满足另外的条件，如例题中的cars < people ，那么就输出elsif下面的字符，如果前面两个条件都不满足的话就输出else里面的内容，都可以配合使用，通过前一节也能知道如果提供的条件不满足后面没有另外的选择就会选择无输出，真值表里面的关系都要熟记
